LED vs Incandescent outdoor floodlights on motion sensor fixture

[RHTPE]

This may not be the correct forum but I had to start somewhere.
I have a Heath-Zenith motion sensor fixture M/N SL-5318-BZ-E (purchased in 2012). In addition to the motion sensor it also has a dual-brightness (DB) feature whereby the lights turn on at half-brightness at dusk. Using a 19.5W LED PAR38 bulb the fixture works fine in test mode, but will only turn on once when the <ON> duration is set to 20 minutes. Once it shuts off, the motion sensor will no longer turn it back on.
I just switched out the bulbs with 72W incandescent PAR38 bulbs for a test tonight.
I know that in automobile applications on the flasher circuit, some LED bulbs require a resister to avoid hyper-flash.
Might a 110VAC circuit with a motion sensor require a similar approach?
My field is civil/structural, not electrical. I know enough to be dangerous but not enough to properly troubleshoot this issue.
I also purchased a later version fixture (Heath-Zenith M/N HZ-5318-BZ, identical features) with the hope that they have improved the circuitry - this fixture is returnable, the other one is not. Heath-Zenith tech support tells me the circuitry hasn't changed over the 9 years since I purchased the older version.

Ralph
Structures Consulting
Northeast USA

 

[BrianPetersen]

No way to know this without knowing the internal design of it and without knowing how they achieve the dual-brightness feature ... but it's not uncommon for LED bulbs to not be designed to be dimmable, and it would not be at all surprising if the circuit driving the bulb is doing it in a way similar to how a dimmer-switch does it.

Is the bulb that you're using, designed to be dimmable? Brief internet search suggests that such bulbs are available.

I have motion-sensing fixtures outside my house, with LED bulbs in them, but without the dual-brightness feature (they're simply on or off), and they work fine, aside from not having much control over their sensitivity.

 

[RHTPE]

@BrianPetersen

Is the bulb that you're using, designed to be dimmable? Brief internet search suggests that such bulbs are available.

The LED bulb IS described as dimmable.
I could live with the motion sensor control only and turn off the dual brightness, however this is how I initially set it up. resulting in the issue as I described - turns on once because of motion, stays on the programmed time, shuts off. After that, motion will NOT turn it on again.
I need to see how how/if it works tonight with an incandescent bulb (after darkness sets in).
If not, then I would suspect that the circuitry is faulty. I will then replace the fixture with the newer version and see if that works.


Ralph
Structures Consulting
Northeast USA

 

[itsmoked]

Sadly there are also several methods of dimming on LED lamps. Some are cheaply sketchy. A different brand with a different look may work fine while a different brand doesn't work right or at all.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[3DDave]

The LED bulb has it's own internal circuit to manage power and the fixture has a circuit to manage power. These may have characteristics that don't work well together. See

https://www.youtube.com/watch?v=z_gC_GXVL4w

 

[RHTPE]

@3DDave:

The LED bulb has it's own internal circuit to manage power and the fixture has a circuit to manage power. These may have characteristics that don't work well together.

Yeah, I get that. After switching to an incandescent bulb tonight, I've concluded that the fixture itself is messed up. When set in the Test mode the motion sensor works (DualBright turned off). However, when leaving DualBright off and switching from Test mode to Timer (triggered on by motion), the light WILL be triggered on by motion - ONCE. After it shuts off, it will NOT be triggered on again by motion. Gonna have to install the newer version tomorrow AM (if it's not raining) and see if that one will function as advertised.

Ralph
Structures Consulting
Northeast USA

 

[cranky108]

Sad to say, I doubt the Heath/Zenith stuff is no longer made, and is likely of an older technology that is not very usable with most LED bulbs. Some of the older designs used a resistor to cut the voltage down, but with the low current draw of the LED, the LED may continue at the same brightness.
Some older technology used a diode or SCR, which was a half-wave rectifier, which depending on the LED, may also reject half the wave form (either stay on, or stay off).

While I don't have this Heath device, I did build several of there kits, and am of an age to understand how they worked.

 

[RHTPE]

@cranky108:

Sad to say, I doubt the Heath/Zenith stuff is no longer made, and is likely of an older technology that is not very usable with most LED bulbs.

Heath-Zenith is still marketed under that name BUT they are made in China. Not impressed with the quality - too many plastic components that won't survive very well when exposed to UV light.
I've given up on the DualBright technology - nice concept I suppose, but not compatible across the board with LED bulbs. I'll just settle for a consistent motion sensor operation.

Ralph
Structures Consulting
Northeast USA